Water is the source of life for most things on this planet, especially when it comes to growing fruits and vegetables. Cannabis plants are very big drinkers, enjoy a heavy feeding, and will reward a grower with an abundant harvest of incredible tasting flowers. Knowing when is the right time to water, the amount to feed and the importance of a good quality growing medium can be a huge difference-maker. In this article we explain what to consider, investing in the right grow medium and our top tips on watering Cannabis plants.
Top Feeding - Done by hand and the most basic way to water any type of plant, top feeding allows water to pass from the top of the pots to the bottom. There will be a point where water is slowly pouring out of the bottom of your pots, meaning as the water is displaced, the pots are flushed with oxygen.
Bottom Feeding - This method involves sitting the pots in a saucer and filling the saucer with water or nutrient solution. The growing medium will then suck the water upwards and will pass through the root zone using capillary action. As Cannabis plants get more mature and develop a well-structured root system, the grower will need to feed more frequently or use a bigger bottom saucer.
Automated Drippers - The base model for commercial large-scale farming, using timers and drippers to ensure a regulated, consistent feeding schedule. Using drippers in living soil set ups will allow the plants to get used to the same amount of nutrient solution each day, at the same time.
The way in which a Cannabis plant will adapt to its environment will be to transpire water available in the growing medium, and the relative humidity in the atmosphere. How much water we add into the grow room can have a major influence on just how much water the plants require.
Over-watering plants will cause the root zone to become waterlogged, meaning levels of dissolved oxygen are dramatically reduced, as well as available air pockets around the root hairs. As a result, nutrient uptake will cease until the right balance is maintained causing plants to slow growth, wilt, and disrupt the transpiration process.
Over-saturated growing mediums will encourage bad bacteria to form around the roots, causing the foul smell and unfavorable conditions for any type of plant.
Plants will wilt to show their state of unhappiness, meaning the leaves will droop down in an effort to not photosynthesize until the right balance is met. Poor drainage and capillary action of the growing medium can cause plants to hold too much water and not enough air pockets.
On the basis of the growing medium has become totally dry and the humidity levels are low, then the plants will show signs by wilting and having a dry and tired appearance. Water is an essential building block for transporting sugars, minerals, and nutrients to the rest of the plants, so you can expect growth and production to slow significantly. Similar to heat stress, leaves will curl up and reduce the surface area in an attempt to hold off on photosynthesis, until optimum levels are met.
Outdoor growers can often face the challenge of keeping plants well-watered. A spike in temperatures and a dry medium will only quickly lead to issues if not sorted.
Some cultivars are able to endure long drying periods, however, over time will begin to display signs of stress and deficiencies. As Cannabis plants develop in size, be vigilant to increase the amount of water or nutrient solution you give them. Some strains can be very nutrient hungry once flowering begins.
Drainage
Having the perfect drainage can be a lifesaver, and is one way to ensure your plants will not be overwatered. Sometimes it is necessary to add different substrates into your soil to improve capillary action, nutrient retention, and drainage.
Coco coir has excellent properties when used as a supplement in a living soil mix. Thanks to its soft and very fine texture and the fact it contains nutrients, coco works great for holding water and nutrients, wicking liquids, and maintaining high levels of oxygen around the root zone during dry periods. In the hydroponics world, coco and perlite mixed at a 50/50 ratio are a very popular choice, due to their excellent ability to go from wet to dry.
Hydroton clay balls again used in hydroponics are a wonderful way to increase the air capacity in the growing medium, improve drainage, and encourage prolific root growth. These nutrient-free, inert pebbles can be used for a long time and will also promote beneficial bacteria and fungi.
The right time to water
The very best way to know when your Cannabis plants need watering no matter how large the container is to pick the pots up when they are totally dry. This is the weight that the pot should be before you feed with water or nutrient solution.
Another great way to assess how dry your growing medium has become is by inserting your index finger down the side of the pot. Once you have pulled it out, there will be signs of moisture on your finger, or it will be completely dry.
If you notice your Cannabis plants are beginning to wilt and look unhappy, then it is a good idea to access if they are showing symptoms of over or underwatering.
As long as you are not overzealous and overwater your plants, then there should be a fine balance of nutrient uptake, photosynthesis, and growth. During hot temperatures, you should be extra vigilant to keep the plants well saturated to avoid heat stress. As you become more familiar with growing certain cultivars, finding which is more nutrient hungry than others takes time and experience.
